Hydrofoil or Whale tail....anygood?

Anyone using Hydrofoils or Whale tails to reduce the bouncing on rough water?

I have read allot of reviews and its a love em or hate em opinion.

I have a 18hp fastwin in excellent shape and it will be going on a Tracker topper 1542 boat. I live in the prairies where it can get windy out of nowhere so i was wondering if a Hydrofoil might help me if the water set rough.

Any input on these things???

looking at this one.

https://reviews.cabelas.com/8815/019100/stingray-speed-xpi-junior-hydrofoil-stabilizer-reviews/reviews.htm?sort=rating

I ran a Stingray Jr on a Nissan 40C for one season. Created more issues than it solved. I think there is limited advantage with them on small outboards without tilt/trim.

The main advantage is to give stearn lift, and get bow down quicker. Not sure how that would help in rough water.

PS: Also, check to see if your anti-cav plate would fit the foil. If it is the early sixties version (like my 64 sporttwin), I don't think they will fit.

When I bought my boat/motor it came with the whaletail already on it. Most of the guys I run with all have them as well. There are a lot of myths out there as to what they are "supposed" to do and what they help with. To my knowledge/understanding they are generally supposed to help get the boat up and out of the water faster, along with helping the boat stay on plane easier at lower speeds. You generally see these on the larger motors from say a 115hp and up to help compensate for the weight of the motore. I personally have not run mine without it to know if it actually provides any benefit, but it seems there are enought people using them that there has to be some sort of method to the madness. One thing I will note, sometimes on corners or at different speeds, it will kick water up a bit by the transom (nothing crazy but noticable)...that to me is the only downfall.

Well for the price i might look into buying one. I have read they help keep the front down which helps in rougher water....

You will need to make sure your motor is raised high enough that the "tail" is out of the water while on plane. If not, it will keep pushing the bow down, causing plowing and handling problems.

I use smart tabs on a couple of my boats. These are more expensive, but can be adjusted seperatly from tilt/trim.

FWIW: In heavy seas I generally trim out to raise the bow to reduce the chance of a wave coming over or stuffing the bow.

They do not help much with rough water - that is all to do with the hull


On the smaller outboards (15-35 hp range) they can (and that is a big can) help with getting up on plane and staying there - if you have hydraulic trim and tilt then use that - it is a better option


I run one on my 25 'rude and it does kick the boat up a little faster.


Smart tabs are really the way to go if you are worried about making speed in rough water

Well making speed isnt the concern. My concern lies in a flat bottom boat plowing through chop, ifit was heavy chop id be going slower anyways.

I guess I'm just trying to get input on the best way to make a Jon boat handle in rougher water.

Thanks for the feed back people.

Most folks have mixed results at best with them. Before you start adding things to the boat/motor make sure you have everything set up correctly to begin with. You have one of the most beloved motors of all time the 22 cu in 18-20 hp OMC motor. Pound-for-pound probabaly one of the best motors ever made. However, vintage OMC motors from this era have sort of an odd leg length. Prior to standardized lengths of approx 15" for "short shaft motors" and 20" for "long shaft motors" the leg was often and odd intermediate length around 18". Too long for be a modern "short" shaft, but too short to me be a modern "long shaft". Most samller boats have a 15" transom height which is fine for modern short shaft motors, but vintage motors tend to hang a little too deep in the water, which impairs performance and creates excess drag. I was in the same boat (so to speak), but it's pretty easy to fix. Ideally, you'd like the ant-vent plate found just above the prop to be level, or even up to 1-1/2" ABOVE the keel (bottom) of the boat. It may sound a little odd at first, but don't worry. All boats are stern heavy. As a result the LU will be sufficiently submerged at idle and low speed to pump plenty of water, while at speed on plane the anti-vent plate should just barely break the surface of the water thereby creating minimal drag and peak performance on the top end. You can buy/build a jackplate to raise the motor to the ideal height (plenty here in the forums to get inspired from), or you can do what I did which is to simply mount the motor as high on the transom as possible, while still being able to fully clamp it in place. The motor doesn't have to "rest" on the transom per se b/c it is the transom clamp that actually does the work. This should raise the motor about 1"-2". It's not quite ideal, but should get you much closer. Old school racers did/do use shims as small as 1/4" to raise/lower their motors to get the best seeds possible, so you might be surprised at what a difference raising the motor even a few inches will do. It certainly made a difference on my set up. You can then adjust the trim to get even better performance. I've found that the second position out from the transom is the best spot for my 14" semi-v tinny + '66 Johnson 20 hp combo. I'm able to get over 20 mph, which is good enough for me.

Yes I noticed the odd length in the shaft. i'm thinking 18inches might be bang on.. I am considering a mini jacker if it sits too low in the water.

The motor was given to me by my father in law. this thing is in amazing condition.. no a drop of dirty grease or dirt under the cover.

I saw it run last summer. it ran really nice. I think im going to replace lower unit oil before i use it. and lube all the pivot points with lithium white grease. Other than that i dont know much about outboards so I hope Its gonna be reliable for me.

A few more pics of the motor.

I've heard that if you install one on a newer motor, your warrenty will be void. Not sure if that's true, but be careful

I have heard that too...i think cause u have to drill 4 screw holes. But my motor is a 1973 so i'm thinking the warranty is no longer good..lol

I have a 67' Fastwin on my 14' Starcraft... and it works great. With the weight of the added floor, decks, and other equipment it still has to do at least 20mph. I haven't clocked it with gps or anything yet (new fishfinder has one, and I am waiting for it to come in the mail) Like other have said it does have that odd shaft length so it may sit a little lower. I am not sure how much raising the motor will increase performance? Does any one know? It seems to run fine now though so why mess with it. I too have a whale tail or hydrofoil on the back. The previous owner installed it and drilled the bolts through the cav. plate. It doesn't bother me having it on there but I guess I have to keep it on there now considering there are 4 holes in the plate. I think it does give you more of a stable ride by keeping the bow down and probably any drag created by it might only slow you down an few mph at most.

Atuck.. i noticed you painted your outboard.. how's that working for you? is it peeling or anything? did u have to pull much of it apart to paint it, or just tape intake holes and grease points?

Atuck,

Sounds like yours would be causing excessive drag. I'd recommend after you get a gps reading. take it off and do another test. Holes in the cav plate don't cause issues.

Before you make your final decision, please watch the video and read the literature.**

I've had both tails and smart tabs. I put smart tabs on three boats and would always use them in lieu of tails. The extra cost is not much when you consider the benefits, IMHO.
regards, Rich

**
https://www.nauticusinc.com/system_overview.htm

you can buy hydrofoils that dont need to be screwed on.you take off the zinc anode,slide the foil on and bolt the anode back on. i have one,works great.

well im not sure what to buy after seeing Smart tabs. I guess i'll have to see how the boat handles and take it from there.

thanks for all the feedback.

FuzzyGrub said:

Atuck,

Sounds like yours would be causing excessive drag. I'd recommend after you get a gps reading. take it off and do another test. Holes in the cav plate don't cause issues.

Click to expand...

Fuzzy,
Here is a pic of how low the cavitation plate sits below the hull. Maybe 2" tops. How much speed should I be getting out of the 18hp? I will have to try with and without once I get the GPS hooked up to see the difference.

Sask tracker 1542 said:

Atuck.. i noticed you painted your outboard.. how's that working for you? is it peeling or anything? did u have to pull much of it apart to paint it, or just tape intake holes and grease points?

Click to expand...

Sask,
The fisrt motor I painted (evinrude 9.5) came out well for my first time. It was a basic engine enamel with self etching as a primer but I didn't use a clear coat. The only place the paint wore off was on the lower unit where the transom saver held it up. I guess the bumps on the road caused it to rub off. The second motor (18hp) I think came out much better. I did better prep work and used better paint along with a clear coat. I also took this one apart as much as I could, but I kept the power head together. (Check out the photos on my build) I am hoping all of this in theory will give me better results. I am working on using a piece of thick cloth or foam on the lower unit when I hook the transom saver up so as to not have the paint come off there again.

Hi Atuck. Here's a pic of where you want to try to set your motor height. You'd like the yellow line on the left, which is level with the anti-vent plate on the motor, to be level or fall between the two yellow lines on the right, the lowest of which is even with the keel and the highest of which is approximately 1-1/2" above the keel. When raised and mounted securely, you should notice increased performance from your motor, particularly on the top end. You should be able to get +/- 20 mph with an 18-20 hp Johnson/E-rude on a 14' tinny, less if you have a lot of gear.